Wireless communication system with selectively sized data transport blocks

ABSTRACT

A wireless transmit receive unit (WTRU) for a code division multiple access (CDMA) telecommunication system utilizes a plurality of protocol layers including a physical layer and a medium access control (MAC) layer such that the MAC layer provides data to the physical layer via plurality of transport channels (TrCHs). Each TrCH is associated with a set of logical channels. The physical layer receives blocks of data for transport such that the transport blocks (TBs) includes a MAC header and logical channel data for a selected logical channel associated with a given TrCH. Each TB has one of a selected limited finite number of TB bit sizes. The logical channel data for each TB has a bit size evenly divisible by a selected integer N greater than three (3). The MAC header for each TB has a bit size such that the MAC header bit size plus the logical channel data bit size equals one of the TB bit sizes. A fixed MAC header bit size is associated with each logical channel for a given TrCH and is selected such that each fixed MAC header bit size equals M modulo N where M is an integer greater than 0 and less than N, i.e. each MAC header for a given TrCH has a bit offset equal to M.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. application Ser. No.09/759,553, filed Jan. 12, 2001 which claims the benefit of U.S.Provisional Application No. 60/176,150, filed Jan. 14, 2000.

[0002] The present invention relates to wireless communication systemsand, in particular, the selective sizing of data blocks for wirelesstransport of data in an efficient manner.

BACKGROUND OF THE INVENTION

[0003] Radio interfaces such as those proposed by the 3rd GenerationPartnership Project (3G) use Transport Channels (TrCHs) for transfer ofuser data and signaling between User Equipment (UE), such as a MobileTerminal (MT), and a Base Station (BS) or other device within node of acommunication network. Generically, UEs, MTs and BSs can be referred toas wireless transmit receive units (WTRUs).

[0004] In 3G Time Division Duplex (TDD), TrCHs are a composite of one ormore physical channels defined by mutually exclusive physical resources.TrCH data is transferred in sequential groups of Transport Blocks (TBs)defined as Transport Block Sets (TBSs). Each TBS is transmitted in agiven Transmission Time Interval (TTI). User Equipment (UE) and BaseStation (BS) physical reception of TrCHs require knowledge of TransportBlock (TB) sizes.

[0005] For each TrCH, a Transport Format Set (TFS) is specifiedcontaining Transport Formats (TFs). Each TF, defines a TBS composed of aspecified number of TBs where each TB preferably has the same sizewithin a given TBS. Thus, a finite number of potential TB sizes aredefined with respect to each TrCH.

[0006] Radio Resource Control (RRC) signaling is required between the BSand UE to define the attributes of each established TrCH, including alist of potential TB sizes. Signaling over the radio interfaceintroduces system overhead, which reduces the physical resourcesavailable for user data transmission. Therefore, it is important tominimize RRC signaling and the number of potential TrCH TB sizesrespectively.

[0007] All data transferred by specific TrCHs must fit into the TB sizesspecified for the TFS of a particular TrCH. However, variable size datablocks exist that can not be predicted, for Radio Access Network (RAN)and Core Network (CN) signaling data, as well as Non-Real Time (NRT)user data transmissions.

[0008] To allow for the transfer of variable size data blocks, a RadioLink Control (RLC) provides a segmentation and re-assembly multiplexingfunction and a padding function. The segmentation and re-assemblymultiplexing function reduces the size prior to transmission RLC and isused when the transferred data block is larger then the maximum allowedTB size. The padding function increases the data block or segmented datablock size by padding with extra bits to fit a TB size.

[0009] Segmentation and re-assembly of data over more than one TTI ispermitted for some, but not all, types of data. In 3G, it is notpermitted, for example, for Common Control Channel (CCCH) logical data.Thus, the payload requirements for a TrCH carrying logical CCCH data areinherently restricted.

[0010] The RLC processing results in blocks of data called Protocol DataUnits (PDUs). A certain amount of each RLC PDU is required for controlinformation. Using a relatively small RLC PDU results in a lowertransfer data to control information ratio consequently resulting in aless efficient use of radio resources. The RLC padding function is usedwhen the transferred data block is not equal to any of the allowed TBsizes. Likewise, the greater the difference between the transferred datablock size and the next larger allowed TB size results in lowering thetransfer data to used physical resources ratio consequently resulting ina less efficient use of radio resources. Therefore, it is important tomaximize the number of potential TB sizes.

[0011] Lowering the number of TB sizes reduces RRC signaling overheadand increases radio interface efficiency. Increasing the number of TBsizes reduces RLC overhead and increases radio interface efficiency. Itis therefore important to make the best use of the specified TB sizesfor each TrCH.

[0012] TB sizes are the sum of the RLC PDU size and a Medium AccessControl (MAC) header size. The MAC header size is dependent of the classof traffic, which is indicated by the Logical Channel type. A TargetChannel Type Field (TCTF) is provided in the MAC header to indicate towhich logical channel a TB is assigned. A TrCH can support multiplelogical channel types. This means that the finite number of allowed TBsizes must support several MAC header sizes.

[0013] For RAN and CN signaling data and NRT user data, the RLCgenerates octet aligned (8 bit quantities) PDU sizes. Thus, the RLC PDUsare defined as groups of a selected number of octets, such that the RLCPDU bit size is always evenly divided by eight, i.e. the RLC PDU bitsize always equals 0 modulo 8. This characteristic is maintained evenwhen padding is required.

[0014] Applicant has recognized that, if MAC header sizes for differentLogical Channel types have mutually exclusive bit offsets, TB sizes cannot be generically used for all transmissions. TB sizes have to bedefined for specific MAC headers and logical channels respectively. Thisincreases signaling overhead and reduces RLC PDU size options, whichresults in less efficient use of radio resources.

[0015] Specifying octet aligned MAC header sizes as is currently done insome 3rd generation systems allows for some sharing of TB sizes betweendifferent Logical Channel types, but also increases MAC signalingoverhead since the MAC header size must be at least 8 bits in suchsituations. In 3rd generation TDD mode, certain TrCH and Logical Channelcombinations have very limited transfer block sizes and increasing MACoverhead should be avoided. Therefore, in TDD, TB size definitions arespecific to Logical Channel specific MAC header bit offsets, and asdescribed, reduces overall radio resource efficiency.

[0016] Applicant has recognized that without common MAC header bitoffsets, it is not possible for MT down-link and BS up-linktransmissions to octet align received frames in a physical layer sincethe bit offset is based on the logical channel type which cannot beknown while at the physical layer. Therefore, TB's have to betransferred to layer 2 for logical channel determination before bitshifting can occur. This means that considerable processing overhead isintroduced for these TrCH's. Applicant has recognized that with TrCHspecific bit aligned MAC headers, bit shifting is known at the physicallayer and no additional processing overhead is introduced.

SUMMARY OF THE INVENTION

[0017] For wireless communication between WTRUs, such as between UEs anda base station, a CDMA telecommunication system utilizes a plurality ofprotocol layers including a physical layer and a medium access control(MAC) layer such that the MAC layer provides data to the physical layervia plurality of transport channels (TrCHs). Each transport channel(TrCH) is associated with a set of logical channels for transportinglogical channel data within transport channel data. At least one TrCH isassociated with a set of logical channels having at least two logicalchannels of different types.

[0018] The physical layer receives blocks of data for transport suchthat the transport blocks (TBs) of data includes of a MAC header andlogical channel data for one of the TrCHs. Each TB transports data for agiven TrCH such that the logical channel data includes data associatedwith a selected logical channel from the set of logical channelsassociated with the given TrCH. Each TB has one of a selected limitedfinite number of TB bit sizes. The logical channel data for each TB hasa bit size evenly divisible by a selected integer N greater than three(3). N is preferably eight (8) so that the logical data is in the formof an RLC PDU defined in terms of octets of data bits. Preferably thedata manipulation and formatting is performed by one or more computerprocessors.

[0019] The MAC header for each TB includes data identifying the selectedlogical channel and has a bit size such that the MAC header bit sizeplus the logical channel data bit size equals one of the TB bit sizes.The MAC header bit size is fixed for TBs transporting data for the sameTrCH and same selected logical channel, but may be different from theMAC header bit size for TBs transporting data for either a differentTrCH or a different selected logical channel.

[0020] Preferably, for TrCHs associated with a set of multiple types oflogical channels, a fixed MAC header bit size is associated with eachlogical channel within the set of logical channels and is selected suchthat each fixed MAC header bit size equals M modulo N where M is aninteger greater than 0 and less than N. This results in a MAC header bitoffset of M which is the same for all MAC headers associated with agiven TrCH. This allows for a MAC header to be smaller than N in size.Thus, when N is 8, such as for octet aligned RLC PDUs, a MAC header canbe smaller than one octet of data.

[0021] Preferably, each MAC header has a data field for data identifyingthe selected type of logical channel associated with the logical channeldata. A bit size of that data field is preferably selected to determinethe modulo N bit size of the MAC header, i.e. the MAC header bit offset.A shortest data field bit size is preferably provided for the data fieldof the MAC header of one or more logical channels of the set associatedwith the respective TrCH such that the logical channels designated bythe shortest data field size are collectively more frequently used withthe respective TrCH than any other logical channel within the associateset of logical channels. Alternatively, the shortest data field bit sizemay be associated with the most restricted TrCH logical channelcombination payload requirement.

[0022] Preferably, the TrCHs includes a forward access channel (FACH)associated with a set of logical channels including a dedicated trafficchannel (DTCH), a dedicated control channel (DCCH), a shared channelcontrol channel (SHCCH), a common control channel (CCCH) and a commontraffic channel (CTCH), and a random access channel (RACH) associatedwith a set of logical channels including the DTCH, the DCCH, the SHCCHand the CCCH. In such case, each MAC header preferably has a TargetChannel Type Field (TCTF) for data identifying the selected logicalchannel type associated with the transport channel data where a bit sizeof the TCTF field is selected to determine the modulo N bit size M ofthe MAC header. The modulo N bit size M of the MAC header is preferably3 modulo 8 for FACH and 2 modulo 8 for RACH.

[0023] The TCTF data field bit size is preferably 3 with respect to FACHMAC headers associated with the CCCH, CTCH, SHCCH and BCCH logicalchannels. The TCTF data field bit size is preferably 5 with respect tothe FACH MAC headers associated with the DCCH and DTCH logical channels.The TCTF data field bit size is preferably 2 with respect to RACH MACheaders associated with the CCCH and SHCCH logical channels. The TCTFdata field bit size is preferably 4 with respect to the RACH MAC headersassociated with the DCCH and DTCH logical channels.

[0024] Other objects and advantages will be apparent to one of ordinaryskill in the art from the following detailed description of a presentlypreferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a simplified illustration of a wireless spread spectrumcommunication system.

[0026]FIG. 2 is an illustration of data flowing into a common or sharedchannel.

[0027]FIG. 3 is an illustration of data flowing into a FACH channelwithin a RNC.

[0028]FIG. 4 is a schematic diagram illustrating a channel mapping withrespect to a MAC layer and a physical layer in a communication systemaccording to the teaching of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0029]FIG. 1 illustrates a simplified wireless spread spectrum codedivision multiple access (CDMA) communication system 18. A node b 26within the system 18 communicates with associated user equipment (UE)20-24 such as a mobile terminal (MT). The node b 26 has a single sitecontroller (SC) 30 associated with either a single base station (BS) 28(shown in FIG. 1) or multiple base stations. Generically, UEs, MTs andBSs can be referred to as wireless transmit receive units (WTRUs).

[0030] A group of node bs 26, 32, 34 is connected to a radio networkcontroller (RNC) 36. To transfer communications between RNCs 36-40, aninterface (IUR) 42 between the RNCs is utilized. Each RNC 36-40 isconnected to a mobile switching center (MSC) 44 which in turn isconnected to the Core Network (CN) 46.

[0031] To communicate within the system 18, many types of communicationchannels are used, such as dedicated, shared and common. Dedicatedphysical channels transfer data between a node b 26 and a particular UE20-24. Common and shared channels are used by multiple UEs 20-24 orusers. All of these channels carry a variety of data including traffic,control and signaling data.

[0032] Since shared and common channels carry data for different users,data is sent using protocol data units (PDUs) or packets. As shown inFIG. 2, to regulate the flow of data from differing sources 48, 50, 52into a channel 56, a controller 54 is used.

[0033] One common channel used for transmitting data to the UEs 20-24 isa forward access channel (FACH) 58. As shown in FIG. 3, the FACH 58originates in a RNC 36 and is sent to a node b 28-34 for wirelesstransmission as a spread spectrum signal to the UEs 20-24. The FACH 58carries several data types from various sources, such as a commoncontrol channel (CCCH), dedicated control and traffic channel (DCCH andDTCH), and a downlink and uplink shared channel (DSCH and USCH) controlsignaling via a shared control logical channel (SHCCH). The FACH 58 alsocarries control signaling out of band and similar data transmitted viathe IUR 42 from other RNCs 38-40, such as CCCH, DCCH and DTCH controldata.

[0034] Various controllers are used by the RNC 36 to control the flow ofdata. A radio link controller (RLC) 64 handles the CCCH. A dedicatedmedium access controller (MAC-d) 66 handles the DCCH and the DTCH. Ashared medium access controller (MAC-sh) 68 handles the DSCH, USCHcontrol signaling. Controlling the FACH 58 is a common medium accesscontroller (MAC-c) 60.

[0035] With reference to FIG. 4, there is illustrated a preferredchannel mapping with respect to the MAC layer 70 and the physical layer72. The transport channels (TrCHs) 74 transport data over the physicallayer 72 to associated physical channels 76. Each of the TrCHs 74 isassociated with one or more logical channels 78. The TrCHs communicateby using transport blocks (TB) which are comprised of a MAC header andassociated logical channel data in a RLC PDU. The MAC header has logicalchannel identification information. Preferably, the RLC PDU is definedby data octets, so that the RLC PDU bit size equals 0 modulo 8.

[0036] Preferably, the TrCHs 74 include a dedicated channel (DCH), adownlink shared channel (DSCH), a common packet channel (CPCH), a randomaccess channel (RACH), a forward access channel (FACH), a paging channel(PCH) and a broadcast channel (BCH). The associated physical channelsinclude a dedicated physical channel (DPDCH), a physical downlink sharedchannel (PDSCH), a physical common packet channel (PCPCH), a physicalrandom access channel (PRACH), a secondary common control physicalchannel (SCCPCH) and a primary common control physical channel (PCCPCH).Other transport and physical channels may be supported, such as anuplink shared channel (USCH) with an associated physical uplink sharedchannel (PUSCH).

[0037] The logical channels preferably include a dedicated trafficchannel (DTCH), a dedicated control channel (DCCH), a shared controlchannel (SHCCH), a common control channel (CCCH), a common trafficchannel (CTCH), a paging control channel (PCCH) and a broadcast controlchannel (BCCH).

[0038] The preferred association of transport channels with physical andlogical channels is illustrated in FIG. 4. For example, the FACH maytransport data to the SCCPCH from any one of the set of logical channelsincluding the DTCH, the DCCH, the SHCCH, the CCCH, or the CTCH.Similarly, the RACH transports data to the PRACH from any one of the setof logical channels including the DTCH, the DCCH, the SHCCH, or theCCCH.

[0039] In order to make efficient use of TBS size definitions, it isdesirable to be able to use all specified TB sizes for all LogicalChannel types supported by a respective TrCH. This allows the number ofspecified TFs for a TFS to be minimized thereby reducing signalingoverhead, while maximizing the number of RLC PDU size options reducingthe overhead associated with RLC segmentation and padding. TB and TBSassignment is accomplished without increasing MAC header sizes for TrCHlogical channel combinations that support limited TB data payloads, i.e.the amount of data processed as a single unit from higher layers withinMAC and RLC.

[0040] A bit aligned MAC header resolves both the radio resourceefficiency issues associated with TB size signaling and RLC segmentationand padding overhead. The alignment is performed by maintaining theminimum size MAC headers for the Logical Channel and TrCH combinationsthat support limited TB data payload sizes, and increasing MAC headersfor non- data payload size sensitive combinations to the same bitoffset.

[0041] For example, if the data payload size limited combinations haveMAC headers of X octets (total octets)+Y bit (extra bit offset, lessthan 8) sizes, and non-limited combination have headers of A octets+Cbits and B octets+D bits. Then the C and D bits are adjusted to match Ybits. In some cases this means A and/or B octets must be incremented byone octet. It is not necessary for A and B octet sizes to match the Xoctet size since TB size=MAC header+RLC PDU and the octet aligned RLCPDU will conform to the available octet size. MAC headers less than anoctet in length are permitted, and in fact desirable, in such cases X, Aor B may be 0.

[0042] All TB sizes specified by RRC signaling for a specific TrCHchannel will have a Y bit offset. That Y bit offset being applicable tothe MAC headers for all Logical Channels supported by the specific TrCH.Since the MAC header octet sizes do not necessarily match betweendifferent Logical Channel types, RLC entities will correspondinglygenerate appropriate RLC PDU sizes to conform to the allowed TB sizes.This does not necessarily mean RLC PDU's have to be resized whenswitching between TrCH types, since it is always possible to adjust thedifference in MAC header size between the new and old TrCH's in theallowed TB sizes.

[0043] With bit aligned MAC headers, each TrCH type may have a differentbit aligned TB size offset. The offset is preferably defined by the mostlimited Logical Channel and TrCH combination block size, which isspecific to the TrCH type. Therefore, each TrCH type has an independentoptimized MAC header bit offset.

[0044] The invention has the additional benefit of removing processorintensive layer 2 bit shifting requirements in the WTRUs, such as the UEand BS equipment. With a common TB size bit offset for all LogicalChannels types supported by a specific TrCH, it is possible for receivedradio transmissions to be bit shifted by the physical layer according tohigher layer requirements. It is advantageous to provide bit shifting atthe physical layer which is already involved in bit manipulationswithout adding additional overhead, as opposed to adding thisrequirement to the higher layer processing requirements.

[0045] In 3G system design, RLC and Radio Resource Control (RRC)entities generate and expect to receive data blocks which start on octetboundaries. If MAC headers for specific TrCH's have variable bit offsetsit is only possible to avoid bit shifting in BS down-link and MT up-linktransmissions. In the MT down-link and BS up-link cases it is notpossible for the physical layer to be aware of the higher layer logicalchannel type that defines the bit offset. Only if the bit offset iscommon for all transmissions across the specific transport channel canbit processing be avoided in communication layers 2 and 3.

[0046] RRC Transport Format Set (TFS) signaling is used to defineTransport Block (TB) sizes for each defined Transport Format (TF)allowed on a specific TrCH. The number of possible TB sizes should beminimized to reduce the signaling load. It is also necessary to chooseTB sizes wisely since RLC PDU padding can dramatically increasetransmission overhead.

[0047] Preferably, there is a maximum of 32 possible TB sizes in eachTrCH's TFS. Specifying all 32 results in a significant signalling loadthat should be avoided. Although it is also important to have as manychoices as possible on transport channels which have variabletransmissions since RLC Acknowledged Mode (AM) and Unacknowledged Mode(UM) PDU's will be padded to match the next larger TB size when theprevious lower size is exceeded.

[0048] The relation between RLC PDU and TB sizes is as follows: TBSize=MAC Header Size+RLC PDU Size.

[0049] In the preferred RLC AM and UM, the PDU size is always octetaligned and in Time Division Duplex (TDD) a variable non-octet alignedMAC header exists. Therefore, MAC individual bit offsets must be takeninto account when specifying the allowed TB sizes.

[0050] In TDD, with the exception of DTCH/DCCH all logical channelcombinations on the FACH and separately on the RACH are modified fromthe prior art to have the same bit offset (+2 bits for RACH and +3 bitsfor FACH when multiple logical channels are allowed). Table 1 reflects apreferred prior art MAC header size specification.

[0051] With the prior art MAC header definitions, octet aligned AM andUM RLC payloads will result in two possible TB size bit offsets on RACHand FACH when multiple logical channel types are applied. Octet+1 or 3bits for FACH and octet+0 or 2 bits for RACH. This potentially doublesthe number of Transport Formats that need to be specified on RACH andFACH. TABLE 1 Prior Art TDD RACH/FACH MAC Header Sizes by LogicalChannel Type UE-id UE- C/T Header Logical CH TrCH TCTF Field Type idField Size DCCH/DTCH FACH 3 2 16/32 4 25/41 CCCH FACH 3 N/A N/A N/A 3CTCH FACH 3 N/A N/A N/A 3 SHCCH FACH 0/3 (Note 1) N/A N/A N/A 0/3 BCCHFACH 3 N/A N/A N/A 3 DCCH/DTCH RACH 2 2 16 4 24  CCCH RACH 2 N/A N/A N/A2 SHCCH RACH 0/2 (Note 1) N/A N/A N/A 0/2

[0052] To increase the efficiency of TFS signaling and allow for moreRLC PDU size choices, it is necessary to have a common TB size bitoffset. Increasing MAC header sizes for CCCH, SHCCH, CTCH and BCCH,should be avoided since these channels operate in RLC TM where RLCsegmentation across multiple radio frame TTIs is not possible.Therefore, the preferred solution is to increase the DCCH/DTCH TCTF by 2bits on RACH and FACH. A preferred coding is reflected in Tables 2 and 3below, respectively for FACH and RACH. This results in common RACH TBsizes of octet+2, i.e. 2 modulo 8, and FACH TB sizes of octet+3, i.e. 3modulo 8.

[0053] Another benefit of MAC header bit alignment is the ability toremove the UE and RNC layer 2 bit shifting requirement. The RLCgenerates and expects to receive octet aligned PDU's. With variable bitshifted MAC headers only the UTRAN Down Link (DL) and UE Up Link (UL)MAC PDU's could avoid layer 2 bit shifting by padding the MAC header andproviding a padding indicator to the physical layer. This is notpossible for the UE DL and UTRAN UL transmissions since physical layeris unaware of the logical channel type on RACH and FACH.

[0054] If the TrCH bit offset is constant for all logical channel typessupported for a given TrCH, the physical layer can pad the MAC header tooctet align the UE DL and UTRAN UL. No padding indicator is needed in ULor DL since the padding is constant for the TrCH.

[0055] The number of TFs specifying TB sizes allowed in each TFS on aspecific TrCH should be minimized to reduce the layer 3 signaling load.It is also necessary to allow a maximum number of octet aligned RLC PDUsizes in AM and UM for efficient transfer of DCCH/DTCH data. In TDD modebit shifted MAC headers potentially doubles the number of TFs that needto be defined on RACH and FACH TrCHs. Additionally, variable bit shiftedMAC headers result in requiring layer 2 bit shifting for all UE DL andUTRAN UL transmissions on RACH and FACH. MAC header bit alignment isdefined to avoid duplication of TB size definitions for octet alignedRLC PDUs and layer 2 bit shifting.

[0056] As in the prior art, the MAC header preferably includes a TargetChannel Type Field (TCTF). The TCTF field is a flag that providesidentification of the logical channel type on FACH and RACH transportchannels, i.e. whether it carries BCCH, CCCH, CTCH, SHCCH or dedicatedlogical channel information. Unlike the prior art, the preferred sizeand coding of TCTF for TDD are shown in Tables 2 and 3.

[0057] Table 2: Coding of the Target Channel Type Field on FACH for TDDTABLE 2 Coding of the Target Channel Type Field on FACH for TDD TCTFDesignation 000 BCCH 001 CCCH 010 CTCH 01100 DCCH or DTCH Over FACH01101-01111 Reserved (PDUs with this coding will be discarded by thisversion of the protocol) 100 SHCCH 101-111 Reserved (PDUs with thiscoding will be discarded by this version of the protocol)

[0058] TABLE 3 Coding of the Target Channel Type Field on RACH for TDDTCTF Designation 00 CCCH 0100 DCCH or DTCH Over RACH 0101-0111 Reserved(PDUs with this coding will be discarded by this version of theprotocol) 10 SHCCH 11 Reserved (PDUs with this coding will be discardedby this version of the protocol)

[0059] Note that the preferred size of the TCTF field of FACH for TDD iseither 3 or 5 bits depending on the value of the 3 most significantbits. The preferred TCTF of the RACH for TDD is either 2 or 4 bitsdepending on the value of the 2 most significant bits.

[0060] Bit aligned MAC headers allow common TB sizes to be defined fordifferent logical channels on the same TrCH. Common TB sizes reducesignalling overhead and potentially increase the options for RLC PDUsizes, which increases system efficiency by reducing the need forpadding in AM and UM.

[0061] This is especially important for RACH and FACH channels where acommon TrCH supports many different traffic types. Optimally for RACHand FACH, each TB size specified can apply to DCCH, CCCH, CTCH, SHCCHand DTCH. To allow this capability in octet mode it is preferred tospecify the total number of octets not just the number of RLC PDUoctets.

[0062] By specifying the total number of octets, it is not necessary toindicate the TDD MAC header type on common channels since the headeroffset is the same for all logical channel types. It is also possible toavoid RLC PDU resizing transport channel switching by taking intoaccount the change in MAC header octet offset.

[0063] Table 4 is a preferred specification for a Transport Format Set(TFS) in a 3G system. TABLE 4 Transport Format Set (TFS) InformationType and Element/Group name Need Multi reference Semantics descriptionCHOICE Transport MP channel type >Dedicated transport The transportchannels channel that is configured with this TFS is of typeDCH >>Dynamic Transport MP 1 to Note 1 Format Information <maxTF> >>>RLCSize MP Integer Unit is bits (0..4992) Note 2 >>>Number of TBs MP 1 toPresent for every and TTI List <maxTF> valid number of TB's (and TTI)for this RLC Size. >>>>Transmission CV- Integer Unit is ms. TimeInterval dynamic (10, 20, TTI 40, 80) >>>>Number of MP Integer Note 3Transport blocks (0..512) >Common transport The transport channelschannel that is configured with this TFS is of a type not equal toDCH >>Dynamic Transport MP 1 to Note Format Information <maxTF> >>>RLCSize MP Integer Unit is bits (0..4992) Note 2 >>>Number of TBs MP 1 toPresent for every and TTI List <maxTF> valid number of TB's (and TTI)for this RLC Size. >>>>Number of MP Integer Note 3 Transport blocks(0..512) >>>>CHOICE mode MP >>>>>FDD (nodata) >>>>>TDD >>>>>Transmission CV- Integer Unit is ms. Time Intervaldynamic (10, 20, TTI 40, 80) >>>CHOICE Logical MP The logical channelsChannel List that are allowed to use this RLC Size >>>>ALL Null Alllogical channels mapped to this transport channel. >>>>Configured NullThe logical channels configured to use this RLC size in the RB mappinginfo. 10.3.4.21 if present in this message or in the previously storedconfiguration otherwise >>>>Explicit List 1 to 15 Lists the logicalchannels that are allowed to use this RLC size. >>>>>RB Identity MP RBidentity 10.3.4.16 >>>>>Logical Channel CV-UL- Integer Indicates therelevant RLC (0..1) UL logical channel for Logical this RB. “0” Channelscorresponds to the first, “1” corresponds to the second UL logicalchannel configured for this RB in the IE “RB mappinginfo”. >>Semi-static MP Semi- Transport Format static InformationTransport Format Information 10.3.5.11 Condition Explanation DynamicTTIThis IE is included if dynamic TTI usage is indicated in IE TransmissionTime Interval in Semi-static Transport Format Information. Otherwise itis not needed. UL-RLCLogicalChannels If “Number of uplink RLC logicalchannels” in IE “RB mapping info” in this message is 2 or the IE “RBmapping info” is not present in this message and 2 UL logical channelsare configured for this RB, then this IE is present. Otherwise this IEis not needed. # Therefore for TDD DCH TrCHs the 4 bit C/T is added ifMAC multiplexing is applied, for FACH the 3 bit TCTF offset is added andfor RACH the 2 bit TCTF offset is added. # configure a transport formatwith number of transport block <> 0, with a zero-size transport block.

[0064] In summary, the invention provides an improvement to a CDMAtelecommunication system that has a physical layer and a MAC layer, withthe MAC layer providing data to the physical layer via a plurality oftransport channels utilizing data transfer blocks of specific sizes foreach channel, with each transport channel associated with a set oflogical channels where for at least one transfer channel the set oflogical channels has at least two logical channels with differentlogical types. One implementation of the invention is preferably in theform of a processor for associating, for a given transport channelassociated with a logical channel set having two (2) different types oflogical channels, a fixed MAC header bit size with each logical channelwithin the set with each fixed MAC header bit size equal M modulo Nwhere N is a selected integer greater than three (3) and M is an integergreater than zero (0) and less than N. The processor is configured toselect a logical channel having logical-channel data for transport froma set of logical channels associated with the given transport channel,with the logical-channel data for each transport block having a bit sizeevenly divisible N. The processor also provides the logical-channel datafrom the MAC layer to the physical layer via the given transport channelas a plurality of transport-blocks of data, with each transport block ofdata including a MAC header and logical-channel data for the transportgiven channel, with each transport block of data having one of a finitenumber of transport block (TB) bit sizes, with a first bit size of afirst MAC header set to a first fixed size for transport blockstransporting data for the same transport channel and same selectedlogical-channel data, with the first bit size of the MAC header plus thefirst bit size of the logical-channel data equal to one of the TB bitsizes, and with a second bit size of a second MAC header set to a secondfixed size for transport blocks transporting data for a differenttransport channel or different selected logical-channel data, with thesecond bit size of the MAC header plus the second bit size of thedifferent logical-channel data equal to one of the TB bit sizes.

[0065] References:

[0066] 3GPP TSG-RAN Working Group 2 Meeting #10, Tdoc R2-00-057

[0067] 3GPP TSG-RAN Working Group 2 Meeting #10, Tdoc R2-00-060

[0068] The following is a listing of acronyms and their meanings as usedherein: AM Acknowledged Mode BCCH Broadcast Control Channel BCHBroadcast Channel BS Base Station CCCH Common Control Channel CDMA CodeDivision Multiple Access CN Core Network CPCH Common Packet Channel CTCHCommon Traffic Channel DCCH Dedicated Control Channel DCH DedicatedChannel DL Down Link DPDCH Dedicated Physical Channel DPSCH PhysicalDownlink Shared Channel DSCH Downlink Shared Channel DTCH DedicatedTraffic Channel FACH Forward Acess Channel MAC Medium Access ControlMAC-c Common Medium Access Control MAC-d Dedicated Medium Access ControlMAC-sh Shared Medium Access Control MSC Mobile Switching Center MTMobile Terminal NRT Non-Real Time PCCPCH Primary Common Control PhysicalChannel PCH Paging Channel PCPCH Physical Common Packet Channel PDUProtocol Data Units PRACH Physical Random Access Channel PUSCH PhysicalUplink Shared Channel RACH Random Access Channel RAN Radio AccessNetwork RLC Radio Link Control RNC Radio Network Controller RRC RadioResource Control SC Site Controller SCCPCH Secondary Common ControlPhysical Channel SHCCH Shared Channel Control Channel TB Transport BlockTCTF Target Channel Type Field TDD Time Division Duplex TF TransportFormat TFS Transport Format Set TrCH Transport Channel UE User EquipmentUL Up Link UM Unacknowledged Mode USCH Uplink Shared Channel WTRUWireless Transmit Receive Unit

What is claimed is:
 1. A wireless transmit receive unit (WTRU) for acode division multiple access (CDMA) telecommunication system having aphysical layer and a medium access control (MAC) layer, with the MAClayer providing data to the physical layer via a plurality of transportchannels utilizing data transfer blocks of specific sizes for eachchannel, with each transport channel associated with a set of logicalchannels where for at least one transfer channel the set of logicalchannels has at least two logical channels with different logical types,the WTRU comprising: a processor configured to associate, for a giventransport channel associated with a logical channel set having two (2)different types of logical channels, a fixed MAC header bit size witheach logical channel within said set with each fixed MAC header bit sizeequal M modulo N where N is a selected integer greater than three (3)and M is an integer greater than zero (0) and less than N; saidprocessor configured to select a logical channel having logical-channeldata for transport from a set of logical channels associated with saidgiven transport channel, with the logical-channel data for eachtransport block having a bit size evenly divisible N; and said processorconfigured to provide the logical-channel data from the MAC layer to thephysical layer via said given transport channel as a plurality oftransport-blocks of data, with each transport block of data including aMAC header and logical-channel data for said transport given channel,with each transport block of data having one of a finite number oftransport block (TB) bit sizes, with a first bit size of a first MACheader set to a first fixed size for transport blocks transporting datafor the same transport channel and same selected logical-channel data,with the first bit size of the MAC header plus the first bit size of thelogical-channel data equal to one of said TB bit sizes, and with asecond bit size of a second MAC header set to a second fixed size fortransport blocks transporting data for a different transport channel ordifferent selected logical-channel data, with the second bit size of theMAC header plus the second bit size of the different logical-channeldata equal to one of said TB bit sizes.
 2. A WTRU according to claim 1wherein said processor is configured to associate a fixed MAC header bitsize with each logical channel, to select a logical channel and toprovide the logical-channel data where N equals 8 and the logical datais in the form of Radio Link Control Protocol Data Units (RLC PDUs) madeup of data octets.
 3. A WTRU according to claim 1 wherein said processoris configured to associate a fixed MAC header bit size with each logicalchannel, to select a logical channel and to provide the logical-channeldata where with respect to said at least one transport channelassociated with a logical channel set having at least two (2) logicalchannels of different types, each MAC header has a data field for dataidentifying the type of the selected logical channel associated with thelogical channel data and wherein a bit size of said data field isselected to determine the modulo N bit size M of the MAC header.
 4. AWTRU according to claim 3 wherein said processor is configured toassociate a fixed MAC header bit size with each logical channel, toselect a logical channel and to provide the logical-channel data wherethe bit size of said data field is selected to be the shortest for thelogical channel which has the most restricted transport channel logicalchannel combination payload requirements with respect to said at leastone transport channel.
 5. A WTRU according to claim 3 wherein saidprocessor is configured to associate a fixed MAC header bit size witheach logical channel, to select a logical channel and to provide thelogical-channel data where a shortest data field bit size is providedfor said data field of the MAC header of one or more logical channels ofthe set associated with said at least one transport channel such thatsaid one or more logical channels are collectively more frequently usedwith said at least one transport channel than any other logical channelwithin said logical channel set associated with said at least onetransport channel.
 6. A WTRU according to claim 1 wherein said processoris configured to associate a fixed MAC header bit size with each logicalchannel, to select a logical channel and to provide the logical-channeldata where at least two transport channels are associated with a set oflogical channels having at least four (4) different types of logicalchannels, wherein, for said at least two transport channels, a fixed MACheader bit size associated with each logical channel within a respectivelogical channel set is selected such that each fixed MAC header bit sizeequals M modulo N where M is an integer less than N and M may bedifferent for MAC headers associated with different transport channels.7. A WTRU according to claim 6 wherein said processor is configured toassociate a fixed MAC header bit size with each logical channel, toselect a logical channel and to provide the logical-channel data where Nequals 8 and the logical data is in the form of Radio Link ControlProtocol Data Units (RLC PDUs) made up of data octets.
 8. A WTRUaccording to claim 7 wherein said processor is configured to associate afixed MAC header bit size with each logical channel, to select a logicalchannel and to provide the logical-channel data where said at least twotransport channels include: a forward access channel (FACH) associatedwith a set of logical channels including a dedicated traffic channel(DTCH), a dedicated control channel (DCCH), a shared channel controlchannel (SHCCH), a common control channel (CCCH) and a common trafficchannel (CTCH), and a random access channel (RACH) associated with a setof logical channels including said DTCH, said DCCH, said SHCCH and saidCCCH.
 9. A WTRU according to claim 8 wherein said processor isconfigured to associate a fixed MAC header bit size with each logicalchannel, to select a logical channel and to provide the logical-channeldata where M equals 3 for each MAC header associated with said logicalchannels for the FACH transport channel and M equals 2 for each MACheader associated with the logical channels for the RACH transportchannel.
 10. A WTRU according to claim 8 wherein said processor isconfigured to associate a fixed MAC header bit size with each logicalchannel, to select a logical channel and to provide the logical-channeldata where, with respect to said FACH and RACH transport channels, eachMAC header has a TCTF data field for data identifying the type of theselected logical channel associated with the transport channel data andwherein a bit size of the TCTF field is selected to determine the moduloN bit size M of the MAC header.
 11. A WTRU according to claim 10 whereinsaid processor is configured to associate a fixed MAC header bit sizewith each logical channel, to select a logical channel and to providethe logical-channel data where the TCTF data field bit size is 3 withrespect to FACH MAC headers associated with the CCCH, CTCH, SHCCH andBCCH logical channels, the TCTF data field bit size is 5 with respect tothe FACH MAC headers associated with the DCCH and DTCH logical channels,the TCTF data field bit size is 2 with respect to RACH MAC headersassociated with the CCCH and SHCCH logical channels, and the TCTF datafield bit size is 4 with respect to the RACH MAC headers associated withthe DCCH and DTCH logical channels.
 12. A WTRU according to claim 11wherein said processor is configured to associate a fixed MAC header bitsize with each logical channel, to select a logical channel and toprovide the logical-channel data where M equals 3 for each MAC headerassociated with said logical channels for the FACH transport channel andM equals 2 for each MAC header associated with the logical channels forthe RACH transport channel.
 13. A WTRU according to claim 1 wherein saidprocessor is configured to associate a fixed MAC header bit size witheach logical channel, to select a logical channel and to provide thelogical-channel data where, for each transport channel associated with aset of at least two logical channels of different types, a fixed MACheader bit size associated with each logical channel within a respectiveset of logical channels is selected such that each fixed MAC header bitsize equals M modulo N where M is a whole number less than N and M maybe different for MAC headers associated with different transportchannels.
 14. A WTRU according to claim 13 wherein said processor isconfigured to associate a fixed MAC header bit size with each logicalchannel, to select a logical channel and to provide the logical-channeldata where N equals 8 and the logical data is in the form of Radio LinkControl Protocol Data Units (RLC PDUs) made up of data octets.
 15. AWTRU according to claim 14 wherein said processor is configured toassociate a fixed MAC header bit size with each logical channel, toselect a logical channel and to provide the logical-channel data wherethere exists at least one transport channel where the value of M for itsassociated MAC header bit sizes is different than the value of M for thefixed MAC header bit sizes for at least one other transport channel. 16.A WTRU according to claim 15 wherein said processor is configured toassociate a fixed MAC header bit size with each logical channel, toselect a logical channel and to provide the logical-channel data wheresaid transport channels include: a forward access channel (FACH)associated with a set of logical channels including a dedicated trafficchannel (DTCH), a dedicated control channel (DCCH), a shared channelcontrol channel (SHCCH), a common control channel (CCCH) and a commontraffic channel (CTCH), and a random access channel (RACH) associatedwith a set of logical channels including said DTCH, said DCCH, saidSHCCH and said CCCH.
 17. A WTRU according to claim 16 wherein saidprocessor is configured to associate a fixed MAC header bit size witheach logical channel, to select a logical channel and to provide thelogical-channel data where M equals 3 for each MAC header associatedwith said logical channels for the FACH transport channel and M equals 2for each MAC header associated with the logical channels for the RACHtransport channel.
 18. A WTRU according to claim 17 wherein saidprocessor is configured to associate a fixed MAC header bit size witheach logical channel, to select a logical channel and to provide thelogical-channel data where, with respect to said FACH and RACH transportchannels, each MAC header has a TCTF data field for data identifying thetype of the selected logical channel associated with the transportchannel data and wherein a bit size of the TCTF field is selected todetermine the modulo N bit size M of the MAC header.
 19. A WTRUaccording to claim 18 wherein said processor is configured to associatea fixed MAC header bit size with each logical channel, to select alogical channel and to provide the logical-channel data where the TCTFdata field bit size is 3 with respect to FACH MAC headers associatedwith the CCCH, CTCH, SHCCH and BCCH logical channels, the TCTF datafield bit size is 5 with respect to the FACH MAC headers associated withthe DCCH and DTCH logical channels, the TCTF data field bit size is 2with respect to RACH MAC headers associated with the CCCH and SHCCHlogical channels, and the TCTF data field bit size is 4 with respect tothe RACH MAC headers associated with the DCCH and DTCH logical channels.20. A method for a wireless transmit receive unit (WTRU) configured foruse in a code division multiple access (CDMA) telecommunication systemhaving a physical layer and a medium access control (MAC) layer, withthe MAC layer providing data to the physical layer via a plurality oftransport channels utilizing data transfer blocks of specific sizes foreach channel, with each transport channel associated with a set oflogical channels where for at least one transfer channel the set oflogical channels has at least two logical channels with differentlogical types, the method comprising the steps of: associating, for agiven transport channel associated with a logical channel set having two(2) different types of logical channels, a fixed MAC header bit sizewith each logical channel within said set with each fixed MAC header bitsize equal M modulo N where N is a selected integer greater than three(3) and M is an integer greater than zero (0) and less than N; selectinga logical channel having logical-channel data for transport from a setof logical channels associated with said given transport channel, withthe logical-channel data for each transport block having a bit sizeevenly divisible N; and providing the logical-channel data from the MAClayer to the physical layer via said given transport channel as aplurality of transport-blocks of data, with each transport block of dataincluding a MAC header and logical-channel data for said transport givenchannel, with each transport block of data having one of a finite numberof transport block (TB) bit sizes, with a first bit size of a first MACheader set to a first fixed size for transport blocks transporting datafor the same transport channel and same selected logical-channel data,with the first bit size of the MAC header plus the first bit size of thelogical-channel data equal to one of said TB bit sizes, and with asecond bit size of a second MAC header set to a second fixed size fortransport blocks transporting data for a different transport channel ordifferent selected logical-channel data, with the second bit size of theMAC header plus the second bit size of the different logical-channeldata equal to one of said TB bit sizes.